Just In: Lapierre e:i Suspension

Electronically controlled mountain bike suspension has come a long way

Just in: a Lapierre Spicy 527 with the new version of the company's e:i electronic rear suspension system. Joe Lindsey

It might seem futuristic, but electronically controlled suspension has actually been around in some form for over 15 years, but it’s always seemed not quite ready for prime time.

One of the first systems debuted in the late 1990s, from K2 and shock partner Noleen. It used a piezoelectric suspension for front and rear, which was dubbed Smart Shock. The system worked reasonably well for the time, but typically failed (sometimes quickly) when it got wet.

As electronics become increasingly part of our riding experience, maybe it’s inevitable that suspension is the next frontier. Lapierre seems to think so, and its e:i shock is a promising step forward.

The e:i system is a Lapierre exclusive, found on some models in its Zesty Trail, Zesty All-Mountain, and Spicy mountain bike lines.

There are three main components: the electronic control system, accelerometer sensors, and the battery.

An LED light indicates which compression damping setting you’re in: red for locked, yellow for pedal, and green for open. The light is solid when in automatic mode, and flashes in manual modes.

In automatic mode, while the rider is pedaling, the system defaults to the lockout compression damping, but shifts to pedal on moderately bumpy terrain and full open mode for big hits. When you’re coasting, the shock automatically switches to open. The user can set three levels of sensitivity, which determine how much force the sensors have to take before the system switches out of lockout mode.

To monitor those forces, the computer receives inputs from accelerometers mounted on the stem, fork, and bottom bracket. The fork itself isn’t controlled by the system, but the sensors relay information on terrain and suspension movement to the computer, which tells the shock motor to switch modes. All that happens in less than a tenth of a second, says Lapierre, and since there are two sensors near the front of the bike, the suspension mode can change before the rear wheel even encounters a bump.

I’ve only had a couple of rides on the system, but they were promising. Our test sled is a Lapierre Spicy 527, a 27.5-inch wheel bike aimed at the enduro market. It comes with RockShox’s excellent Pike RC fork (160mm travel) and Monarch rear shock (150mm travel).

In automatic mode, the suspension switches cleanly and easily between compression damping settings. The LED constantly changes colors depending on which setting it’s in, but it’s tough to even glance at while riding. Your primary clue the system is working is the sound of the motor switching settings, which is very much like the sound an electronic front derailleur makes when shifting.

There’s a slight lag when you coast before the system switches to open mode. (When you’re coasting you’re not trying to counteract pedal forces, so you don’t need a really efficient suspension.) In the most aggressive sensitivity setting, the bike requires a pretty significant hit to switch from locked to pedal, and noticeably less so in the other two sensitivity levels.

From the rider’s standpoint, the system is fairly elegant. Lapierre streamlined the computer to a one-button interface and did away with the control screen from the first version released in 2014. There are external wires for the fork sensor and computer and the battery is mounted externally, but the rest are tucked inside the frame. The bottom bracket sensor and wires are entirely inside the frame.

We have no long-term experience on the bike yet, and mountain biking’s punishing conditions, particularly in enduro-style riding, are notoriously hard on gear. With sensitive electronic components in the fork and bottom bracket, it remains to be seen how durable the system is, and easy to maintain. Look for a longer-term review of the system later this year.

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